"We are saddened by this vicious act of hatred," CAIR said in a statement, adding "Americans of all faiths must join together to reject the kind of extremist ideologies that can lead to such inexcusable and unconscionable acts."

Former FBI Counterterrorism expert John Guandolo in March noted to Arutz Sheva that CAIR was established by Islamist leaders closely linked to the radical Muslim Brotherhood, of which Hamas is an offshoot, to provide propaganda and other forms of nonviolent support for Hamas.

Guandolo noted that the FBI in 1993 documented a key meeting of the US-Palestine Committee, a front group for the Muslim Brotherhood, which two founders of CAIR attended.

It is worth noting that terrorists in Hamas-governed Gaza rained a barrage of rockets on Israel in mid-March, peppering the Jewish state with at least 100 missiles in three days. Hamas is recognized as a terror group in the US.

"Twisted irony" - KKK leader shot Christians, not Jews

The shooter, who killed three on Sunday outside the Overland Park Jewish Community Center (JCC) and at a nearby assisted living residence, Village Shalom, was later identified as a former Ku Klux Klan (KKK) leader. Two of his victims, Dr. William Lewis Corporon and Reat Griffin Underwood, were identified as members of the United Methodist Church of the Resurrection in Leawood.

Rabbi Daniel Rockoff, of the Oberland Park orthodox synagogue "Beit Yisrael," on Monday noted the irony of the shooting while talking to NRG Maariv.

"It's ironic that the murderer shouted 'heil Hitler,' but instead of killing Jews, he killed Christians. It's ironic and twisted at the same time," remarked Rabbi Rockoff. "I don't know how to explain it - it certainly could have been Jews."

The identity of the third victim, a woman in her 70s who was killed at the Village Shalom assisted living residence, has yet to be revealed.

The shooter asked people whether they were Jewish before opening fire, according to Rabbi Herbert Mandl, chaplain for the Overland Park Police Department, who spoke to CNN.

"The community is still trying to digest what happened here today, it's unbelievable," noted Rabbi Rockoff. Speaking about the JCC, he added "all the Jewish activities take place there, and there's a Jewish school there...also the assisted living residence where the third murder happened is a pride of the Jewish community."

The rabbi added that he intends to bring professionals to the Jewish community to treat trauma from the attack. "One of the community members was just opposite the murderer, and instead of shooting him, he hit the windows of his car. He's really shaken up."

Obama condemns "heartbreaking shooting"

FBI statistics reveal that nearly two thirds of anti-religious hate crimes in the US target Jews or Jewish sites, reports AFP.

US President Barack Obama responded to the attack, condemning the shooting as "horrific," and pledging the government's "full support" to the community and the investigation.

Adding his condolences, Overland Park Police Department Chief John Douglass stated "today is a very sad and tragic day and certainly, there are no words to express the senselessness of what's happened this afternoon."

The local JCC similarly released a statement saying "our hearts go out to the families who have suffered loss on this tragic day."